WAGENINGEN EVALUATING PROGRAMS
FOR ANALYTICAL LABORATORIES
Certificate of Analysis
International Biomass Exchange Program
REFERENCE MATERIAL
BIMEP sample 440
Consensus Values
BIMEP 440
General Information
In this report an overview is given of analytical data for this sample collected in our proficiency testing program. The consensus values are calculated using a
robust statistical model. With this NDA model mean and standard deviation are calculated using all reported data when at least 8 results are left after removal
of reported 'lower than' (<) and 0 (= zero) values. No outliers are removed.
This report is divided into three sections: Consensus Values, Indicative Values and Values for Information. The division is made on the reliability of the data.
Consensus Values are based on at least 16 results while the coefficient of variation is smaller than 25 %. Indicative Values are based on at least 8 and less
than 16 results or a coefficient of variation between 25 % and 50 %. Other values, based on less than 8 results or a coefficient of variation higher than 50 %,
are given for information only.
In the section with Consensus Values the following parameters are given: mean, standard deviation, coefficient of variation, number of results, median and
MAD (Median of Absolute Deviation). The confidence limits (at 95 % probabilty) are calculated for these determinands.
In the section with Indicative Values the following parameters are given: mean, standard deviation, coefficient of variation, number of results, median and
MAD.
In the section with Information Values the following parameters are given: median, MAD and number of results. For determinands which have at least 5 results
reported as smaller than (<) the median of these ‘smaller than results’ is calculated. In some cases this median of ‘<’ values is much smaller than median and
mean of the indicative values. This may be caused by a too opmistic (too low) value for the detection limit reported by a (small) majority of participating
laboratories who report ‘<’-values.
All values, expressed on a weight basis (kg or %), are reported in ovendry (105 °C) material. Moisture is reported in the material as received.
Sample information
WEPAL reference materials are from natural sources only. There is no spiking, mixing or other alterations of the samples. For sample preparation the BIMEP
o
samples are dried at 40 C and milled to pass a 0.5 mm sieve.
This BIMEP sample 440 of Rosa (plant) / Rosa l. from Netherlands is prepared for the WEPAL proficiency programs. The sample is used in 1 period (or
round). The results on which the values in this report are based were taken from the period given in the following table.
Year
2011
Period
3
Number
2
2
Indicative Values
BIMEP 440
Method: General Analysis
Element
Unit
Ash
g/kg
Calorific Value (gross)
MJ/kg
Moisture
g/kg
Volatile Matter
g/kg
Mean
33.4
19.0
75.3
759
Std.Dev.
0.76
0.27
4.01
11.5
CV %
2.3
1.4
5.3
1.5
N
12
12
12
10
Median
33.3
18.9
76.1
761
MAD
0.55
0.19
2.71
8.1
Method: Elementary Analysis
Element
Unit
Carbon (C)
g/kg
Cl
g/kg
Hydrogen (H)
g/kg
Nitrogen (N)
g/kg
S
g/kg
Mean
483
0.328
58.2
13.4
0.779
Std.Dev.
9.0
0.0667
1.60
0.89
0.1205
CV %
1.9
20.3
2.8
6.7
15.5
N
12
9
11
11
10
Median
483
0.323
58.1
13.1
0.778
MAD
6.0
0.0431
1.06
0.60
0.0915
3
Informative Values
Method: Water Soluble Elements
Element
Unit
Cl
g/kg
K
g/kg
Na
g/kg
Median
0.270
7.31
10.3
MAD
0.0751
-
N
3
1
1
Method: Major Elements
Element
Al
Ca
Fe
K
Mg
Na
P
Si
Unit
g/kg
g/kg
g/kg
g/kg
g/kg
g/kg
g/kg
g/kg
Median
0.0930
5.00
0.100
7.90
1.33
0.122
2.00
0.727
MAD
0.0130
0.260
0.0400
0.340
0.032
0.0220
0.030
0.1270
N
5
5
5
5
5
5
5
4
Method: Minor Elements
Element
As
Ba
Cd
Co
Cr
Cu
F
Hg
Mn
Mo
Ni
Pb
Sb
Se
Sn
Ti
Tl
V
Zn
Unit
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
Median
0.458
5.15
0.149
1.05
1.88
3.44
32.0
0.0110
39.2
0.850
0.700
1.61
0.255
1.30
3.41
0.600
47.3
MAD
0.0500
1.210
0.0560
0.550
0.218
0.106
22.34
2.03
0.5500
0.1460
0.313
0.0450
1.437
2.13
N
4
6
3
2
2
3
2
1
6
2
3
4
2
0
1
4
0
1
5
BIMEP 440
Results smaller than (<)
Median of <
N
4
1.000
1.00
5
5
1.000
5